Removed dynamic loading on macos.

lua.mod/lua-5.1.4/src/loadlib.c

@@ -1,666 +1,583 @@
-/*
-** $Id: loadlib.c,v 1.52.1.3 2008/08/06 13:29:28 roberto Exp $
-** Dynamic library loader for Lua
-** See Copyright Notice in lua.h
-**
-** This module contains an implementation of loadlib for Unix systems
-** that have dlfcn, an implementation for Darwin (Mac OS X), an
-** implementation for Windows, and a stub for other systems.
-*/
-
-
-#include <stdlib.h>
-#include <string.h>
-
-
-#define loadlib_c
-#define LUA_LIB
-
-#include "lua.h"
-
-#include "lauxlib.h"
-#include "lualib.h"
-
-
-/* prefix for open functions in C libraries */
-#define LUA_POF		"luaopen_"
-
-/* separator for open functions in C libraries */
-#define LUA_OFSEP	"_"
-
-
-#define LIBPREFIX	"LOADLIB: "
-
-#define POF		LUA_POF
-#define LIB_FAIL	"open"
-
-
-/* error codes for ll_loadfunc */
-#define ERRLIB		1
-#define ERRFUNC		2
-
-#define setprogdir(L)		((void)0)
-
-
-static void ll_unloadlib (void *lib);
-static void *ll_load (lua_State *L, const char *path);
-static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym);
-
-
-
-#if defined(LUA_DL_DLOPEN)
-/*
-** {========================================================================
-** This is an implementation of loadlib based on the dlfcn interface.
-** The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD,
-** NetBSD, AIX 4.2, HPUX 11, and  probably most other Unix flavors, at least
-** as an emulation layer on top of native functions.
-** =========================================================================
-*/
-
-#include <dlfcn.h>
-
-static void ll_unloadlib (void *lib) {
-  dlclose(lib);
-}
-
-
-static void *ll_load (lua_State *L, const char *path) {
-  void *lib = dlopen(path, RTLD_NOW);
-  if (lib == NULL) lua_pushstring(L, dlerror());
-  return lib;
-}
-
-
-static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
-  lua_CFunction f = (lua_CFunction)dlsym(lib, sym);
-  if (f == NULL) lua_pushstring(L, dlerror());
-  return f;
-}
-
-/* }====================================================== */
-
-
-
-#elif defined(LUA_DL_DLL)
-/*
-** {======================================================================
-** This is an implementation of loadlib for Windows using native functions.
-** =======================================================================
-*/
-
-#include <windows.h>
-
-
-#undef setprogdir
-
-static void setprogdir (lua_State *L) {
-  char buff[MAX_PATH + 1];
-  char *lb;
-  DWORD nsize = sizeof(buff)/sizeof(char);
-  DWORD n = GetModuleFileNameA(NULL, buff, nsize);
-  if (n == 0 || n == nsize || (lb = strrchr(buff, '\\')) == NULL)
-    luaL_error(L, "unable to get ModuleFileName");
-  else {
-    *lb = '\0';
-    luaL_gsub(L, lua_tostring(L, -1), LUA_EXECDIR, buff);
-    lua_remove(L, -2);  /* remove original string */
-  }
-}
-
-
-static void pusherror (lua_State *L) {
-  int error = GetLastError();
-  char buffer[128];
-  if (FormatMessageA(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM,
-      NULL, error, 0, buffer, sizeof(buffer), NULL))
-    lua_pushstring(L, buffer);
-  else
-    lua_pushfstring(L, "system error %d\n", error);
-}
-
-static void ll_unloadlib (void *lib) {
-  FreeLibrary((HINSTANCE)lib);
-}
-
-
-static void *ll_load (lua_State *L, const char *path) {
-  HINSTANCE lib = LoadLibraryA(path);
-  if (lib == NULL) pusherror(L);
-  return lib;
-}
-
-
-static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
-  lua_CFunction f = (lua_CFunction)GetProcAddress((HINSTANCE)lib, sym);
-  if (f == NULL) pusherror(L);
-  return f;
-}
-
-/* }====================================================== */
-
-
-
-#elif defined(LUA_DL_DYLD)
-/*
-** {======================================================================
-** Native Mac OS X / Darwin Implementation
-** =======================================================================
-*/
-
-#include <mach-o/dyld.h>
-
-
-/* Mac appends a `_' before C function names */
-#undef POF
-#define POF	"_" LUA_POF
-
-
-static void pusherror (lua_State *L) {
-  const char *err_str;
-  const char *err_file;
-  NSLinkEditErrors err;
-  int err_num;
-  NSLinkEditError(&err, &err_num, &err_file, &err_str);
-  lua_pushstring(L, err_str);
-}
-
-
-static const char *errorfromcode (NSObjectFileImageReturnCode ret) {
-  switch (ret) {
-    case NSObjectFileImageInappropriateFile:
-      return "file is not a bundle";
-    case NSObjectFileImageArch:
-      return "library is for wrong CPU type";
-    case NSObjectFileImageFormat:
-      return "bad format";
-    case NSObjectFileImageAccess:
-      return "cannot access file";
-    case NSObjectFileImageFailure:
-    default:
-      return "unable to load library";
-  }
-}
-
-
-static void ll_unloadlib (void *lib) {
-  NSUnLinkModule((NSModule)lib, NSUNLINKMODULE_OPTION_RESET_LAZY_REFERENCES);
-}
-
-
-static void *ll_load (lua_State *L, const char *path) {
-  NSObjectFileImage img;
-  NSObjectFileImageReturnCode ret;
-  /* this would be a rare case, but prevents crashing if it happens */
-  if(!_dyld_present()) {
-    lua_pushliteral(L, "dyld not present");
-    return NULL;
-  }
-  ret = NSCreateObjectFileImageFromFile(path, &img);
-  if (ret == NSObjectFileImageSuccess) {
-    NSModule mod = NSLinkModule(img, path, NSLINKMODULE_OPTION_PRIVATE |
-                       NSLINKMODULE_OPTION_RETURN_ON_ERROR);
-    NSDestroyObjectFileImage(img);
-    if (mod == NULL) pusherror(L);
-    return mod;
-  }
-  lua_pushstring(L, errorfromcode(ret));
-  return NULL;
-}
-
-
-static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
-  NSSymbol nss = NSLookupSymbolInModule((NSModule)lib, sym);
-  if (nss == NULL) {
-    lua_pushfstring(L, "symbol " LUA_QS " not found", sym);
-    return NULL;
-  }
-  return (lua_CFunction)NSAddressOfSymbol(nss);
-}
-
-/* }====================================================== */
-
-
-
-#else
-/*
-** {======================================================
-** Fallback for other systems
-** =======================================================
-*/
-
-#undef LIB_FAIL
-#define LIB_FAIL	"absent"
-
-
-#define DLMSG	"dynamic libraries not enabled; check your Lua installation"
-
-
-static void ll_unloadlib (void *lib) {
-  (void)lib;  /* to avoid warnings */
-}
-
-
-static void *ll_load (lua_State *L, const char *path) {
-  (void)path;  /* to avoid warnings */
-  lua_pushliteral(L, DLMSG);
-  return NULL;
-}
-
-
-static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
-  (void)lib; (void)sym;  /* to avoid warnings */
-  lua_pushliteral(L, DLMSG);
-  return NULL;
-}
-
-/* }====================================================== */
-#endif
-
-
-
-static void **ll_register (lua_State *L, const char *path) {
-  void **plib;
-  lua_pushfstring(L, "%s%s", LIBPREFIX, path);
-  lua_gettable(L, LUA_REGISTRYINDEX);  /* check library in registry? */
-  if (!lua_isnil(L, -1))  /* is there an entry? */
-    plib = (void **)lua_touserdata(L, -1);
-  else {  /* no entry yet; create one */
-    lua_pop(L, 1);
-    plib = (void **)lua_newuserdata(L, sizeof(const void *));
-    *plib = NULL;
-    luaL_getmetatable(L, "_LOADLIB");
-    lua_setmetatable(L, -2);
-    lua_pushfstring(L, "%s%s", LIBPREFIX, path);
-    lua_pushvalue(L, -2);
-    lua_settable(L, LUA_REGISTRYINDEX);
-  }
-  return plib;
-}
-
-
-/*
-** __gc tag method: calls library's `ll_unloadlib' function with the lib
-** handle
-*/
-static int gctm (lua_State *L) {
-  void **lib = (void **)luaL_checkudata(L, 1, "_LOADLIB");
-  if (*lib) ll_unloadlib(*lib);
-  *lib = NULL;  /* mark library as closed */
-  return 0;
-}
-
-
-static int ll_loadfunc (lua_State *L, const char *path, const char *sym) {
-  void **reg = ll_register(L, path);
-  if (*reg == NULL) *reg = ll_load(L, path);
-  if (*reg == NULL)
-    return ERRLIB;  /* unable to load library */
-  else {
-    lua_CFunction f = ll_sym(L, *reg, sym);
-    if (f == NULL)
-      return ERRFUNC;  /* unable to find function */
-    lua_pushcfunction(L, f);
-    return 0;  /* return function */
-  }
-}
-
-
-static int ll_loadlib (lua_State *L) {
-  const char *path = luaL_checkstring(L, 1);
-  const char *init = luaL_checkstring(L, 2);
-  int stat = ll_loadfunc(L, path, init);
-  if (stat == 0)  /* no errors? */
-    return 1;  /* return the loaded function */
-  else {  /* error; error message is on stack top */
-    lua_pushnil(L);
-    lua_insert(L, -2);
-    lua_pushstring(L, (stat == ERRLIB) ?  LIB_FAIL : "init");
-    return 3;  /* return nil, error message, and where */
-  }
-}
-
-
-
-/*
-** {======================================================
-** 'require' function
-** =======================================================
-*/
-
-
-static int readable (const char *filename) {
-  FILE *f = fopen(filename, "r");  /* try to open file */
-  if (f == NULL) return 0;  /* open failed */
-  fclose(f);
-  return 1;
-}
-
-
-static const char *pushnexttemplate (lua_State *L, const char *path) {
-  const char *l;
-  while (*path == *LUA_PATHSEP) path++;  /* skip separators */
-  if (*path == '\0') return NULL;  /* no more templates */
-  l = strchr(path, *LUA_PATHSEP);  /* find next separator */
-  if (l == NULL) l = path + strlen(path);
-  lua_pushlstring(L, path, l - path);  /* template */
-  return l;
-}
-
-
-static const char *findfile (lua_State *L, const char *name,
-                                           const char *pname) {
-  const char *path;
-  name = luaL_gsub(L, name, ".", LUA_DIRSEP);
-  lua_getfield(L, LUA_ENVIRONINDEX, pname);
-  path = lua_tostring(L, -1);
-  if (path == NULL)
-    luaL_error(L, LUA_QL("package.%s") " must be a string", pname);
-  lua_pushliteral(L, "");  /* error accumulator */
-  while ((path = pushnexttemplate(L, path)) != NULL) {
-    const char *filename;
-    filename = luaL_gsub(L, lua_tostring(L, -1), LUA_PATH_MARK, name);
-    lua_remove(L, -2);  /* remove path template */
-    if (readable(filename))  /* does file exist and is readable? */
-      return filename;  /* return that file name */
-    lua_pushfstring(L, "\n\tno file " LUA_QS, filename);
-    lua_remove(L, -2);  /* remove file name */
-    lua_concat(L, 2);  /* add entry to possible error message */
-  }
-  return NULL;  /* not found */
-}
-
-
-static void loaderror (lua_State *L, const char *filename) {
-  luaL_error(L, "error loading module " LUA_QS " from file " LUA_QS ":\n\t%s",
-                lua_tostring(L, 1), filename, lua_tostring(L, -1));
-}
-
-
-static int loader_Lua (lua_State *L) {
-  const char *filename;
-  const char *name = luaL_checkstring(L, 1);
-  filename = findfile(L, name, "path");
-  if (filename == NULL) return 1;  /* library not found in this path */
-  if (luaL_loadfile(L, filename) != 0)
-    loaderror(L, filename);
-  return 1;  /* library loaded successfully */
-}
-
-
-static const char *mkfuncname (lua_State *L, const char *modname) {
-  const char *funcname;
-  const char *mark = strchr(modname, *LUA_IGMARK);
-  if (mark) modname = mark + 1;
-  funcname = luaL_gsub(L, modname, ".", LUA_OFSEP);
-  funcname = lua_pushfstring(L, POF"%s", funcname);
-  lua_remove(L, -2);  /* remove 'gsub' result */
-  return funcname;
-}
-
-
-static int loader_C (lua_State *L) {
-  const char *funcname;
-  const char *name = luaL_checkstring(L, 1);
-  const char *filename = findfile(L, name, "cpath");
-  if (filename == NULL) return 1;  /* library not found in this path */
-  funcname = mkfuncname(L, name);
-  if (ll_loadfunc(L, filename, funcname) != 0)
-    loaderror(L, filename);
-  return 1;  /* library loaded successfully */
-}
-
-
-static int loader_Croot (lua_State *L) {
-  const char *funcname;
-  const char *filename;
-  const char *name = luaL_checkstring(L, 1);
-  const char *p = strchr(name, '.');
-  int stat;
-  if (p == NULL) return 0;  /* is root */
-  lua_pushlstring(L, name, p - name);
-  filename = findfile(L, lua_tostring(L, -1), "cpath");
-  if (filename == NULL) return 1;  /* root not found */
-  funcname = mkfuncname(L, name);
-  if ((stat = ll_loadfunc(L, filename, funcname)) != 0) {
-    if (stat != ERRFUNC) loaderror(L, filename);  /* real error */
-    lua_pushfstring(L, "\n\tno module " LUA_QS " in file " LUA_QS,
-                       name, filename);
-    return 1;  /* function not found */
-  }
-  return 1;
-}
-
-
-static int loader_preload (lua_State *L) {
-  const char *name = luaL_checkstring(L, 1);
-  lua_getfield(L, LUA_ENVIRONINDEX, "preload");
-  if (!lua_istable(L, -1))
-    luaL_error(L, LUA_QL("package.preload") " must be a table");
-  lua_getfield(L, -1, name);
-  if (lua_isnil(L, -1))  /* not found? */
-    lua_pushfstring(L, "\n\tno field package.preload['%s']", name);
-  return 1;
-}
-
-
-static const int sentinel_ = 0;
-#define sentinel	((void *)&sentinel_)
-
-
-static int ll_require (lua_State *L) {
-  const char *name = luaL_checkstring(L, 1);
-  int i;
-  lua_settop(L, 1);  /* _LOADED table will be at index 2 */
-  lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
-  lua_getfield(L, 2, name);
-  if (lua_toboolean(L, -1)) {  /* is it there? */
-    if (lua_touserdata(L, -1) == sentinel)  /* check loops */
-      luaL_error(L, "loop or previous error loading module " LUA_QS, name);
-    return 1;  /* package is already loaded */
-  }
-  /* else must load it; iterate over available loaders */
-  lua_getfield(L, LUA_ENVIRONINDEX, "loaders");
-  if (!lua_istable(L, -1))
-    luaL_error(L, LUA_QL("package.loaders") " must be a table");
-  lua_pushliteral(L, "");  /* error message accumulator */
-  for (i=1; ; i++) {
-    lua_rawgeti(L, -2, i);  /* get a loader */
-    if (lua_isnil(L, -1))
-      luaL_error(L, "module " LUA_QS " not found:%s",
-                    name, lua_tostring(L, -2));
-    lua_pushstring(L, name);
-    lua_call(L, 1, 1);  /* call it */
-    if (lua_isfunction(L, -1))  /* did it find module? */
-      break;  /* module loaded successfully */
-    else if (lua_isstring(L, -1))  /* loader returned error message? */
-      lua_concat(L, 2);  /* accumulate it */
-    else
-      lua_pop(L, 1);
-  }
-  lua_pushlightuserdata(L, sentinel);
-  lua_setfield(L, 2, name);  /* _LOADED[name] = sentinel */
-  lua_pushstring(L, name);  /* pass name as argument to module */
-  lua_call(L, 1, 1);  /* run loaded module */
-  if (!lua_isnil(L, -1))  /* non-nil return? */
-    lua_setfield(L, 2, name);  /* _LOADED[name] = returned value */
-  lua_getfield(L, 2, name);
-  if (lua_touserdata(L, -1) == sentinel) {   /* module did not set a value? */
-    lua_pushboolean(L, 1);  /* use true as result */
-    lua_pushvalue(L, -1);  /* extra copy to be returned */
-    lua_setfield(L, 2, name);  /* _LOADED[name] = true */
-  }
-  return 1;
-}
-
-/* }====================================================== */
-
-
-
-/*
-** {======================================================
-** 'module' function
-** =======================================================
-*/
-  
-
-static void setfenv (lua_State *L) {
-  lua_Debug ar;
-  if (lua_getstack(L, 1, &ar) == 0 ||
-      lua_getinfo(L, "f", &ar) == 0 ||  /* get calling function */
-      lua_iscfunction(L, -1))
-    luaL_error(L, LUA_QL("module") " not called from a Lua function");
-  lua_pushvalue(L, -2);
-  lua_setfenv(L, -2);
-  lua_pop(L, 1);
-}
-
-
-static void dooptions (lua_State *L, int n) {
-  int i;
-  for (i = 2; i <= n; i++) {
-    lua_pushvalue(L, i);  /* get option (a function) */
-    lua_pushvalue(L, -2);  /* module */
-    lua_call(L, 1, 0);
-  }
-}
-
-
-static void modinit (lua_State *L, const char *modname) {
-  const char *dot;
-  lua_pushvalue(L, -1);
-  lua_setfield(L, -2, "_M");  /* module._M = module */
-  lua_pushstring(L, modname);
-  lua_setfield(L, -2, "_NAME");
-  dot = strrchr(modname, '.');  /* look for last dot in module name */
-  if (dot == NULL) dot = modname;
-  else dot++;
-  /* set _PACKAGE as package name (full module name minus last part) */
-  lua_pushlstring(L, modname, dot - modname);
-  lua_setfield(L, -2, "_PACKAGE");
-}
-
-
-static int ll_module (lua_State *L) {
-  const char *modname = luaL_checkstring(L, 1);
-  int loaded = lua_gettop(L) + 1;  /* index of _LOADED table */
-  lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
-  lua_getfield(L, loaded, modname);  /* get _LOADED[modname] */
-  if (!lua_istable(L, -1)) {  /* not found? */
-    lua_pop(L, 1);  /* remove previous result */
-    /* try global variable (and create one if it does not exist) */
-    if (luaL_findtable(L, LUA_GLOBALSINDEX, modname, 1) != NULL)
-      return luaL_error(L, "name conflict for module " LUA_QS, modname);
-    lua_pushvalue(L, -1);
-    lua_setfield(L, loaded, modname);  /* _LOADED[modname] = new table */
-  }
-  /* check whether table already has a _NAME field */
-  lua_getfield(L, -1, "_NAME");
-  if (!lua_isnil(L, -1))  /* is table an initialized module? */
-    lua_pop(L, 1);
-  else {  /* no; initialize it */
-    lua_pop(L, 1);
-    modinit(L, modname);
-  }
-  lua_pushvalue(L, -1);
-  setfenv(L);
-  dooptions(L, loaded - 1);
-  return 0;
-}
-
-
-static int ll_seeall (lua_State *L) {
-  luaL_checktype(L, 1, LUA_TTABLE);
-  if (!lua_getmetatable(L, 1)) {
-    lua_createtable(L, 0, 1); /* create new metatable */
-    lua_pushvalue(L, -1);
-    lua_setmetatable(L, 1);
-  }
-  lua_pushvalue(L, LUA_GLOBALSINDEX);
-  lua_setfield(L, -2, "__index");  /* mt.__index = _G */
-  return 0;
-}
-
-
-/* }====================================================== */
-
-
-
-/* auxiliary mark (for internal use) */
-#define AUXMARK		"\1"
-
-static void setpath (lua_State *L, const char *fieldname, const char *envname,
-                                   const char *def) {
-  const char *path = getenv(envname);
-  if (path == NULL)  /* no environment variable? */
-    lua_pushstring(L, def);  /* use default */
-  else {
-    /* replace ";;" by ";AUXMARK;" and then AUXMARK by default path */
-    path = luaL_gsub(L, path, LUA_PATHSEP LUA_PATHSEP,
-                              LUA_PATHSEP AUXMARK LUA_PATHSEP);
-    luaL_gsub(L, path, AUXMARK, def);
-    lua_remove(L, -2);
-  }
-  setprogdir(L);
-  lua_setfield(L, -2, fieldname);
-}
-
-
-static const luaL_Reg pk_funcs[] = {
-  {"loadlib", ll_loadlib},
-  {"seeall", ll_seeall},
-  {NULL, NULL}
-};
-
-
-static const luaL_Reg ll_funcs[] = {
-  {"module", ll_module},
-  {"require", ll_require},
-  {NULL, NULL}
-};
-
-
-static const lua_CFunction loaders[] =
-  {loader_preload, loader_Lua, loader_C, loader_Croot, NULL};
-
-
-LUALIB_API int luaopen_package (lua_State *L) {
-  int i;
-  /* create new type _LOADLIB */
-  luaL_newmetatable(L, "_LOADLIB");
-  lua_pushcfunction(L, gctm);
-  lua_setfield(L, -2, "__gc");
-  /* create `package' table */
-  luaL_register(L, LUA_LOADLIBNAME, pk_funcs);
-#if defined(LUA_COMPAT_LOADLIB) 
-  lua_getfield(L, -1, "loadlib");
-  lua_setfield(L, LUA_GLOBALSINDEX, "loadlib");
-#endif
-  lua_pushvalue(L, -1);
-  lua_replace(L, LUA_ENVIRONINDEX);
-  /* create `loaders' table */
-  lua_createtable(L, 0, sizeof(loaders)/sizeof(loaders[0]) - 1);
-  /* fill it with pre-defined loaders */
-  for (i=0; loaders[i] != NULL; i++) {
-    lua_pushcfunction(L, loaders[i]);
-    lua_rawseti(L, -2, i+1);
-  }
-  lua_setfield(L, -2, "loaders");  /* put it in field `loaders' */
-  setpath(L, "path", LUA_PATH, LUA_PATH_DEFAULT);  /* set field `path' */
-  setpath(L, "cpath", LUA_CPATH, LUA_CPATH_DEFAULT); /* set field `cpath' */
-  /* store config information */
-  lua_pushliteral(L, LUA_DIRSEP "\n" LUA_PATHSEP "\n" LUA_PATH_MARK "\n"
-                     LUA_EXECDIR "\n" LUA_IGMARK);
-  lua_setfield(L, -2, "config");
-  /* set field `loaded' */
-  luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 2);
-  lua_setfield(L, -2, "loaded");
-  /* set field `preload' */
-  lua_newtable(L);
-  lua_setfield(L, -2, "preload");
-  lua_pushvalue(L, LUA_GLOBALSINDEX);
-  luaL_register(L, NULL, ll_funcs);  /* open lib into global table */
-  lua_pop(L, 1);
-  return 1;  /* return 'package' table */
-}
-
+/*
+** $Id: loadlib.c,v 1.52.1.3 2008/08/06 13:29:28 roberto Exp $
+** Dynamic library loader for Lua
+** See Copyright Notice in lua.h
+**
+** This module contains an implementation of loadlib for Unix systems
+** that have dlfcn, an implementation for Darwin (Mac OS X), an
+** implementation for Windows, and a stub for other systems.
+*/
+
+
+#include <stdlib.h>
+#include <string.h>
+
+
+#define loadlib_c
+#define LUA_LIB
+
+#include "lua.h"
+
+#include "lauxlib.h"
+#include "lualib.h"
+
+
+/* prefix for open functions in C libraries */
+#define LUA_POF		"luaopen_"
+
+/* separator for open functions in C libraries */
+#define LUA_OFSEP	"_"
+
+
+#define LIBPREFIX	"LOADLIB: "
+
+#define POF		LUA_POF
+#define LIB_FAIL	"open"
+
+
+/* error codes for ll_loadfunc */
+#define ERRLIB		1
+#define ERRFUNC		2
+
+#define setprogdir(L)		((void)0)
+
+
+static void ll_unloadlib (void *lib);
+static void *ll_load (lua_State *L, const char *path);
+static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym);
+
+
+
+#if defined(LUA_DL_DLOPEN)
+/*
+** {========================================================================
+** This is an implementation of loadlib based on the dlfcn interface.
+** The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD,
+** NetBSD, AIX 4.2, HPUX 11, and  probably most other Unix flavors, at least
+** as an emulation layer on top of native functions.
+** =========================================================================
+*/
+
+#include <dlfcn.h>
+
+static void ll_unloadlib (void *lib) {
+  dlclose(lib);
+}
+
+
+static void *ll_load (lua_State *L, const char *path) {
+  void *lib = dlopen(path, RTLD_NOW);
+  if (lib == NULL) lua_pushstring(L, dlerror());
+  return lib;
+}
+
+
+static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
+  lua_CFunction f = (lua_CFunction)dlsym(lib, sym);
+  if (f == NULL) lua_pushstring(L, dlerror());
+  return f;
+}
+
+/* }====================================================== */
+
+
+
+#elif defined(LUA_DL_DLL)
+/*
+** {======================================================================
+** This is an implementation of loadlib for Windows using native functions.
+** =======================================================================
+*/
+
+#include <windows.h>
+
+
+#undef setprogdir
+
+static void setprogdir (lua_State *L) {
+  char buff[MAX_PATH + 1];
+  char *lb;
+  DWORD nsize = sizeof(buff)/sizeof(char);
+  DWORD n = GetModuleFileNameA(NULL, buff, nsize);
+  if (n == 0 || n == nsize || (lb = strrchr(buff, '\\')) == NULL)
+    luaL_error(L, "unable to get ModuleFileName");
+  else {
+    *lb = '\0';
+    luaL_gsub(L, lua_tostring(L, -1), LUA_EXECDIR, buff);
+    lua_remove(L, -2);  /* remove original string */
+  }
+}
+
+
+static void pusherror (lua_State *L) {
+  int error = GetLastError();
+  char buffer[128];
+  if (FormatMessageA(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM,
+      NULL, error, 0, buffer, sizeof(buffer), NULL))
+    lua_pushstring(L, buffer);
+  else
+    lua_pushfstring(L, "system error %d\n", error);
+}
+
+static void ll_unloadlib (void *lib) {
+  FreeLibrary((HINSTANCE)lib);
+}
+
+
+static void *ll_load (lua_State *L, const char *path) {
+  HINSTANCE lib = LoadLibraryA(path);
+  if (lib == NULL) pusherror(L);
+  return lib;
+}
+
+
+static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
+  lua_CFunction f = (lua_CFunction)GetProcAddress((HINSTANCE)lib, sym);
+  if (f == NULL) pusherror(L);
+  return f;
+}
+
+/* }====================================================== */
+
+#else
+/*
+** {======================================================
+** Fallback for other systems
+** =======================================================
+*/
+
+#undef LIB_FAIL
+#define LIB_FAIL	"absent"
+
+
+#define DLMSG	"dynamic libraries not enabled; check your Lua installation"
+
+
+static void ll_unloadlib (void *lib) {
+  (void)lib;  /* to avoid warnings */
+}
+
+
+static void *ll_load (lua_State *L, const char *path) {
+  (void)path;  /* to avoid warnings */
+  lua_pushliteral(L, DLMSG);
+  return NULL;
+}
+
+
+static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
+  (void)lib; (void)sym;  /* to avoid warnings */
+  lua_pushliteral(L, DLMSG);
+  return NULL;
+}
+
+/* }====================================================== */
+#endif
+
+
+
+static void **ll_register (lua_State *L, const char *path) {
+  void **plib;
+  lua_pushfstring(L, "%s%s", LIBPREFIX, path);
+  lua_gettable(L, LUA_REGISTRYINDEX);  /* check library in registry? */
+  if (!lua_isnil(L, -1))  /* is there an entry? */
+    plib = (void **)lua_touserdata(L, -1);
+  else {  /* no entry yet; create one */
+    lua_pop(L, 1);
+    plib = (void **)lua_newuserdata(L, sizeof(const void *));
+    *plib = NULL;
+    luaL_getmetatable(L, "_LOADLIB");
+    lua_setmetatable(L, -2);
+    lua_pushfstring(L, "%s%s", LIBPREFIX, path);
+    lua_pushvalue(L, -2);
+    lua_settable(L, LUA_REGISTRYINDEX);
+  }
+  return plib;
+}
+
+
+/*
+** __gc tag method: calls library's `ll_unloadlib' function with the lib
+** handle
+*/
+static int gctm (lua_State *L) {
+  void **lib = (void **)luaL_checkudata(L, 1, "_LOADLIB");
+  if (*lib) ll_unloadlib(*lib);
+  *lib = NULL;  /* mark library as closed */
+  return 0;
+}
+
+
+static int ll_loadfunc (lua_State *L, const char *path, const char *sym) {
+  void **reg = ll_register(L, path);
+  if (*reg == NULL) *reg = ll_load(L, path);
+  if (*reg == NULL)
+    return ERRLIB;  /* unable to load library */
+  else {
+    lua_CFunction f = ll_sym(L, *reg, sym);
+    if (f == NULL)
+      return ERRFUNC;  /* unable to find function */
+    lua_pushcfunction(L, f);
+    return 0;  /* return function */
+  }
+}
+
+
+static int ll_loadlib (lua_State *L) {
+  const char *path = luaL_checkstring(L, 1);
+  const char *init = luaL_checkstring(L, 2);
+  int stat = ll_loadfunc(L, path, init);
+  if (stat == 0)  /* no errors? */
+    return 1;  /* return the loaded function */
+  else {  /* error; error message is on stack top */
+    lua_pushnil(L);
+    lua_insert(L, -2);
+    lua_pushstring(L, (stat == ERRLIB) ?  LIB_FAIL : "init");
+    return 3;  /* return nil, error message, and where */
+  }
+}
+
+
+
+/*
+** {======================================================
+** 'require' function
+** =======================================================
+*/
+
+
+static int readable (const char *filename) {
+  FILE *f = fopen(filename, "r");  /* try to open file */
+  if (f == NULL) return 0;  /* open failed */
+  fclose(f);
+  return 1;
+}
+
+
+static const char *pushnexttemplate (lua_State *L, const char *path) {
+  const char *l;
+  while (*path == *LUA_PATHSEP) path++;  /* skip separators */
+  if (*path == '\0') return NULL;  /* no more templates */
+  l = strchr(path, *LUA_PATHSEP);  /* find next separator */
+  if (l == NULL) l = path + strlen(path);
+  lua_pushlstring(L, path, l - path);  /* template */
+  return l;
+}
+
+
+static const char *findfile (lua_State *L, const char *name,
+                                           const char *pname) {
+  const char *path;
+  name = luaL_gsub(L, name, ".", LUA_DIRSEP);
+  lua_getfield(L, LUA_ENVIRONINDEX, pname);
+  path = lua_tostring(L, -1);
+  if (path == NULL)
+    luaL_error(L, LUA_QL("package.%s") " must be a string", pname);
+  lua_pushliteral(L, "");  /* error accumulator */
+  while ((path = pushnexttemplate(L, path)) != NULL) {
+    const char *filename;
+    filename = luaL_gsub(L, lua_tostring(L, -1), LUA_PATH_MARK, name);
+    lua_remove(L, -2);  /* remove path template */
+    if (readable(filename))  /* does file exist and is readable? */
+      return filename;  /* return that file name */
+    lua_pushfstring(L, "\n\tno file " LUA_QS, filename);
+    lua_remove(L, -2);  /* remove file name */
+    lua_concat(L, 2);  /* add entry to possible error message */
+  }
+  return NULL;  /* not found */
+}
+
+
+static void loaderror (lua_State *L, const char *filename) {
+  luaL_error(L, "error loading module " LUA_QS " from file " LUA_QS ":\n\t%s",
+                lua_tostring(L, 1), filename, lua_tostring(L, -1));
+}
+
+
+static int loader_Lua (lua_State *L) {
+  const char *filename;
+  const char *name = luaL_checkstring(L, 1);
+  filename = findfile(L, name, "path");
+  if (filename == NULL) return 1;  /* library not found in this path */
+  if (luaL_loadfile(L, filename) != 0)
+    loaderror(L, filename);
+  return 1;  /* library loaded successfully */
+}
+
+
+static const char *mkfuncname (lua_State *L, const char *modname) {
+  const char *funcname;
+  const char *mark = strchr(modname, *LUA_IGMARK);
+  if (mark) modname = mark + 1;
+  funcname = luaL_gsub(L, modname, ".", LUA_OFSEP);
+  funcname = lua_pushfstring(L, POF"%s", funcname);
+  lua_remove(L, -2);  /* remove 'gsub' result */
+  return funcname;
+}
+
+
+static int loader_C (lua_State *L) {
+  const char *funcname;
+  const char *name = luaL_checkstring(L, 1);
+  const char *filename = findfile(L, name, "cpath");
+  if (filename == NULL) return 1;  /* library not found in this path */
+  funcname = mkfuncname(L, name);
+  if (ll_loadfunc(L, filename, funcname) != 0)
+    loaderror(L, filename);
+  return 1;  /* library loaded successfully */
+}
+
+
+static int loader_Croot (lua_State *L) {
+  const char *funcname;
+  const char *filename;
+  const char *name = luaL_checkstring(L, 1);
+  const char *p = strchr(name, '.');
+  int stat;
+  if (p == NULL) return 0;  /* is root */
+  lua_pushlstring(L, name, p - name);
+  filename = findfile(L, lua_tostring(L, -1), "cpath");
+  if (filename == NULL) return 1;  /* root not found */
+  funcname = mkfuncname(L, name);
+  if ((stat = ll_loadfunc(L, filename, funcname)) != 0) {
+    if (stat != ERRFUNC) loaderror(L, filename);  /* real error */
+    lua_pushfstring(L, "\n\tno module " LUA_QS " in file " LUA_QS,
+                       name, filename);
+    return 1;  /* function not found */
+  }
+  return 1;
+}
+
+
+static int loader_preload (lua_State *L) {
+  const char *name = luaL_checkstring(L, 1);
+  lua_getfield(L, LUA_ENVIRONINDEX, "preload");
+  if (!lua_istable(L, -1))
+    luaL_error(L, LUA_QL("package.preload") " must be a table");
+  lua_getfield(L, -1, name);
+  if (lua_isnil(L, -1))  /* not found? */
+    lua_pushfstring(L, "\n\tno field package.preload['%s']", name);
+  return 1;
+}
+
+
+static const int sentinel_ = 0;
+#define sentinel	((void *)&sentinel_)
+
+
+static int ll_require (lua_State *L) {
+  const char *name = luaL_checkstring(L, 1);
+  int i;
+  lua_settop(L, 1);  /* _LOADED table will be at index 2 */
+  lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
+  lua_getfield(L, 2, name);
+  if (lua_toboolean(L, -1)) {  /* is it there? */
+    if (lua_touserdata(L, -1) == sentinel)  /* check loops */
+      luaL_error(L, "loop or previous error loading module " LUA_QS, name);
+    return 1;  /* package is already loaded */
+  }
+  /* else must load it; iterate over available loaders */
+  lua_getfield(L, LUA_ENVIRONINDEX, "loaders");
+  if (!lua_istable(L, -1))
+    luaL_error(L, LUA_QL("package.loaders") " must be a table");
+  lua_pushliteral(L, "");  /* error message accumulator */
+  for (i=1; ; i++) {
+    lua_rawgeti(L, -2, i);  /* get a loader */
+    if (lua_isnil(L, -1))
+      luaL_error(L, "module " LUA_QS " not found:%s",
+                    name, lua_tostring(L, -2));
+    lua_pushstring(L, name);
+    lua_call(L, 1, 1);  /* call it */
+    if (lua_isfunction(L, -1))  /* did it find module? */
+      break;  /* module loaded successfully */
+    else if (lua_isstring(L, -1))  /* loader returned error message? */
+      lua_concat(L, 2);  /* accumulate it */
+    else
+      lua_pop(L, 1);
+  }
+  lua_pushlightuserdata(L, sentinel);
+  lua_setfield(L, 2, name);  /* _LOADED[name] = sentinel */
+  lua_pushstring(L, name);  /* pass name as argument to module */
+  lua_call(L, 1, 1);  /* run loaded module */
+  if (!lua_isnil(L, -1))  /* non-nil return? */
+    lua_setfield(L, 2, name);  /* _LOADED[name] = returned value */
+  lua_getfield(L, 2, name);
+  if (lua_touserdata(L, -1) == sentinel) {   /* module did not set a value? */
+    lua_pushboolean(L, 1);  /* use true as result */
+    lua_pushvalue(L, -1);  /* extra copy to be returned */
+    lua_setfield(L, 2, name);  /* _LOADED[name] = true */
+  }
+  return 1;
+}
+
+/* }====================================================== */
+
+
+
+/*
+** {======================================================
+** 'module' function
+** =======================================================
+*/
+  
+
+static void setfenv (lua_State *L) {
+  lua_Debug ar;
+  if (lua_getstack(L, 1, &ar) == 0 ||
+      lua_getinfo(L, "f", &ar) == 0 ||  /* get calling function */
+      lua_iscfunction(L, -1))
+    luaL_error(L, LUA_QL("module") " not called from a Lua function");
+  lua_pushvalue(L, -2);
+  lua_setfenv(L, -2);
+  lua_pop(L, 1);
+}
+
+
+static void dooptions (lua_State *L, int n) {
+  int i;
+  for (i = 2; i <= n; i++) {
+    lua_pushvalue(L, i);  /* get option (a function) */
+    lua_pushvalue(L, -2);  /* module */
+    lua_call(L, 1, 0);
+  }
+}
+
+
+static void modinit (lua_State *L, const char *modname) {
+  const char *dot;
+  lua_pushvalue(L, -1);
+  lua_setfield(L, -2, "_M");  /* module._M = module */
+  lua_pushstring(L, modname);
+  lua_setfield(L, -2, "_NAME");
+  dot = strrchr(modname, '.');  /* look for last dot in module name */
+  if (dot == NULL) dot = modname;
+  else dot++;
+  /* set _PACKAGE as package name (full module name minus last part) */
+  lua_pushlstring(L, modname, dot - modname);
+  lua_setfield(L, -2, "_PACKAGE");
+}
+
+
+static int ll_module (lua_State *L) {
+  const char *modname = luaL_checkstring(L, 1);
+  int loaded = lua_gettop(L) + 1;  /* index of _LOADED table */
+  lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
+  lua_getfield(L, loaded, modname);  /* get _LOADED[modname] */
+  if (!lua_istable(L, -1)) {  /* not found? */
+    lua_pop(L, 1);  /* remove previous result */
+    /* try global variable (and create one if it does not exist) */
+    if (luaL_findtable(L, LUA_GLOBALSINDEX, modname, 1) != NULL)
+      return luaL_error(L, "name conflict for module " LUA_QS, modname);
+    lua_pushvalue(L, -1);
+    lua_setfield(L, loaded, modname);  /* _LOADED[modname] = new table */
+  }
+  /* check whether table already has a _NAME field */
+  lua_getfield(L, -1, "_NAME");
+  if (!lua_isnil(L, -1))  /* is table an initialized module? */
+    lua_pop(L, 1);
+  else {  /* no; initialize it */
+    lua_pop(L, 1);
+    modinit(L, modname);
+  }
+  lua_pushvalue(L, -1);
+  setfenv(L);
+  dooptions(L, loaded - 1);
+  return 0;
+}
+
+
+static int ll_seeall (lua_State *L) {
+  luaL_checktype(L, 1, LUA_TTABLE);
+  if (!lua_getmetatable(L, 1)) {
+    lua_createtable(L, 0, 1); /* create new metatable */
+    lua_pushvalue(L, -1);
+    lua_setmetatable(L, 1);
+  }
+  lua_pushvalue(L, LUA_GLOBALSINDEX);
+  lua_setfield(L, -2, "__index");  /* mt.__index = _G */
+  return 0;
+}
+
+
+/* }====================================================== */
+
+
+
+/* auxiliary mark (for internal use) */
+#define AUXMARK		"\1"
+
+static void setpath (lua_State *L, const char *fieldname, const char *envname,
+                                   const char *def) {
+  const char *path = getenv(envname);
+  if (path == NULL)  /* no environment variable? */
+    lua_pushstring(L, def);  /* use default */
+  else {
+    /* replace ";;" by ";AUXMARK;" and then AUXMARK by default path */
+    path = luaL_gsub(L, path, LUA_PATHSEP LUA_PATHSEP,
+                              LUA_PATHSEP AUXMARK LUA_PATHSEP);
+    luaL_gsub(L, path, AUXMARK, def);
+    lua_remove(L, -2);
+  }
+  setprogdir(L);
+  lua_setfield(L, -2, fieldname);
+}
+
+
+static const luaL_Reg pk_funcs[] = {
+  {"loadlib", ll_loadlib},
+  {"seeall", ll_seeall},
+  {NULL, NULL}
+};
+
+
+static const luaL_Reg ll_funcs[] = {
+  {"module", ll_module},
+  {"require", ll_require},
+  {NULL, NULL}
+};
+
+
+static const lua_CFunction loaders[] =
+  {loader_preload, loader_Lua, loader_C, loader_Croot, NULL};
+
+
+LUALIB_API int luaopen_package (lua_State *L) {
+  int i;
+  /* create new type _LOADLIB */
+  luaL_newmetatable(L, "_LOADLIB");
+  lua_pushcfunction(L, gctm);
+  lua_setfield(L, -2, "__gc");
+  /* create `package' table */
+  luaL_register(L, LUA_LOADLIBNAME, pk_funcs);
+#if defined(LUA_COMPAT_LOADLIB) 
+  lua_getfield(L, -1, "loadlib");
+  lua_setfield(L, LUA_GLOBALSINDEX, "loadlib");
+#endif
+  lua_pushvalue(L, -1);
+  lua_replace(L, LUA_ENVIRONINDEX);
+  /* create `loaders' table */
+  lua_createtable(L, 0, sizeof(loaders)/sizeof(loaders[0]) - 1);
+  /* fill it with pre-defined loaders */
+  for (i=0; loaders[i] != NULL; i++) {
+    lua_pushcfunction(L, loaders[i]);
+    lua_rawseti(L, -2, i+1);
+  }
+  lua_setfield(L, -2, "loaders");  /* put it in field `loaders' */
+  setpath(L, "path", LUA_PATH, LUA_PATH_DEFAULT);  /* set field `path' */
+  setpath(L, "cpath", LUA_CPATH, LUA_CPATH_DEFAULT); /* set field `cpath' */
+  /* store config information */
+  lua_pushliteral(L, LUA_DIRSEP "\n" LUA_PATHSEP "\n" LUA_PATH_MARK "\n"
+                     LUA_EXECDIR "\n" LUA_IGMARK);
+  lua_setfield(L, -2, "config");
+  /* set field `loaded' */
+  luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 2);
+  lua_setfield(L, -2, "loaded");
+  /* set field `preload' */
+  lua_newtable(L);
+  lua_setfield(L, -2, "preload");
+  lua_pushvalue(L, LUA_GLOBALSINDEX);
+  luaL_register(L, NULL, ll_funcs);  /* open lib into global table */
+  lua_pop(L, 1);
+  return 1;  /* return 'package' table */
+}
+